As is well-recognized in the art of sheet processing, a need commonly exists for providing a conveying path of various lengths between an end of one sheet processing apparatus and another downstream sheet processing apparatus in order to advance sheet articles on the conveying path from the first apparatus to the second. This task can be difficult since space restrictions usually exist when operatively configuring sheet processing components.
To provide a conveying path of various lengths between the delivery end of one sheet processing apparatus and another downstream sheet processing apparatus, it has been common in the past to utilize an adjustably extendable and retractable extension table with a plurality of belts thereon for advancing sheet articles. The extension table utilizes a translational method of extension and includes a sliding belt and pulley mechanism that fixedly protrudes in a direction toward the downstream sheet processing apparatus in order for the extension table to be extendable. One disadvantage to such an extension table is that it can only be placed as close to a downstream sheet processing apparatus as the fixedly protruding sliding mechanism will allow. It has therefore not heretofore been possible to position such an extension table in a completely abutting manner to a downstream sheet processing apparatus since doing so would require the protruding sliding mechanism to protrude into the abutting downstream sheet processing apparatus. Another disadvantage suffered by such an extension table is that tension in the belts thereof typically has to be adjusted manually by adjustment of hardware associated therewith for the extension table to be extended to various lengths.
In light of the prior art extension table as discussed hereinabove, there remains much room for improvement in the art for an extension apparatus and method providing a selectively adjustable conveying path for sheet articles between the delivery end of one sheet processing apparatus and another downstream sheet processing apparatus where the extension apparatus can abut a downstream sheet processing apparatus and wherein tension on the belts of the extension apparatus can remain constant when the extension apparatus is extended or retracted without manual adjustment thereof.